Brian, a scientist, is writing a research paper on projectile motion. during one of his experiments, he throws a ball from a point marked as point a, with a certain velocity in the horizontal direction. the ball travels a total horizontal distance of 0.6 meter after 1 second, 1.2 meters after 2 seconds, 1.8 meters after 3 seconds, and so on. it hits the ground on the 8th second. brian marks the point where the ball landed as point b. calculate the distance between point a and point b.